The objective of this study was to evaluate the influence of low-dose combined oral contraception (COC) on basal and stimulated (1 μg ACTH test) levels of serum and salivary cortisol (F), cortisone and on basal serum cortisol binding globulin (CBG), adrenocorticotropic hormone (ACTH), dehydroepiadrosterone (DHEA) and calculated free cortisol in healthy young women. Three-month administration of COC resulted in 1) significant increase of basal (454.0±125.0 to 860.9±179.7 nmol/l) and ACTH-stimulated serum cortisol in 30th min (652.3±60.5 to 1374.1±240.6 nmol/l); 2) no significant change of basal (15.4±7.3 to 18.9±8.5 nmol/l) and ACTH-stimulated salivary cortisol at the 30th min (32.4±8.8 to 32.9±9.0 nmol/l); 3) no significant change of basal serum cortisone (38,8±7.68 to 45.2±24.2 nmol/l) and ACTH-stimulated cortisone at the 30th (34.8±10.9 to 47.0±35.7 nmol/l); 4) significant increase of basal ACTH (17.2±9.0 to 38.2±29.4 ng/l), CBG (991.0±161.0 to 2332.0±428.0 nmol/l), and 5) no significant change of basal DHEA (24.6±15.7 to 22.6±11.7 μmol/l) and calculated basal value for free cortisol (22.8±14.9 to 19.2±6.9nmol/l). In conclusions, higher basal and ACTH-stimulated serum cortisol were found after three-month administration of COC, while basal and stimulated salivary cortisol were not significantly affected. Therefore, salivary cortisol can be used for assessment of adrenal function in women regularly using COC., K. Šimůnková, L. Stárka, M. Hill, L. Kříž, R. Hampl, K. Vondra., and Obsahuje bibliografii a bibliografické odkazy
This study aimed to examine relationships between DHEA(S), anthropometric parameters, oral glucose tolerance test derived data and lipid spectra in a Czech non-diabetic population. 380 healthy volunteers both with and without a family history of diabetes type 2 (DM2) were en rolled into the study (women: n=235, age 28.9±9.4 years, BMI 22.3±4.5 kg/m2, men: n=145, age 32.3±10.0 years, BMI 24.7±3.6 kg/m2). Spearman’s correlations (both without and with the adjustment for age, age and BMI), as well as ANCOVA were used. Non-adjusted data showed many “beneficial” correlations between DHEA(S) and both anthropometric and metabolic variables. Statistical analysis revealed that almost all correlations of DHEA(S) to adiposity and fat distribution in men as well as in women disappeared after the adjustment. There are, however, differences between men and women in the correlation of DHEA(S) to insulin sensitivity and lipid levels. The use of hormonal contraceptives (COC) is also an important factor in this relationship. In men and also in women using COC, DHEA-S after adjustment correlated positively with fasting and stimulated glucose, insulin and C-peptide, and negatively with insulin sensitivity. In this respect, the benefit of DHEA(S) supplementation seems - at least in terms of its alleged antiobesity and antidiabetogenic effects - to be more than controversial., B. Bendlová, J. Vrbíková, M. Hill, M. Vaňková, P. Lukášová, J. Včelák, D. Vejražková, K. Dvořáková, R. Hampl, K. Vondra, L. Stárka., and Obsahuje bibliografii a bibliografické odkazy
Melatonin plays a key role in the circadian timing system. At present, many other functions of melatonin are known. Question remains whether changes in endogenous melatonin may be associated with food intake. Hence, the levels of melatonin, C-peptide and glucose were followed during a daily regimen (16 hours) including standardized food intake using commercial kits. The diurnal profiles of the hormones and serum glucose were evaluated using ANOVA with Period and Subject as independent factors. Pearson’s correlations and using a multiple stepwise backward regression model consisting of the time factor as a polynomial, and serum C-peptide and glucose assessed the correlations between melatonin and the remaining parameters. Our results showed a significant negative correlation between melatonin and C-peptide. The profile of melatonin was physiological, decreasing after wake-up, showing minor changes during the daytime and increasing in the evening. As documented, lesser alterations were indicated in the course of the melatonin daytime profile, which may reflect periodic food intake. Food intake is not the primary factor influencing the melatonin course. While previous studies have mostly considered the protective effect of melatonin in diabetic subjects, our study brought the results suggesting food intake as a factor contributing to daytime melatonin variation in humans. However, the physiological role of melatonin association with food intake in daytime remains in question and should be further investigated., L. Stárka, M. Dušková, B. Rácz, K. Šimůnková, M. Hill, R. Kancheva., and Obsahuje bibliografii a bibliografické odkazy
Leptin, a cytokine-like hormone secreted by adipocytes, is known to regulate food intake but has also emerged as a significant factor in the regulation of bone mass. In humans, states of energy deprivation with low serum leptin have been associated with low bone mass. In mice, leptin deficiency led to increased trabecular bone mass with overall decrease in cortical bone. Leptin regulates bone metabolism indirectly in the hypothalamus thereby activating the sympathetic nervous system (SNS). In addition to the SNS, leptin also interacts with various hypothalamic neuropeptides, such as cocaine- and amphetamine-regulated transcript, neuropeptide Y and/or neuromedin U, which might modulate the effects of leptin on bone. In osteoblasts sympathetic signaling is further gated by the transcriptional factors called molecular clock. As a result, bone loss is accelerated showing that the central effect of leptin seems to be antiosteogenic. Additionally, leptin has a direct anabolic effect within the bone driving the differentiation of bone marrow stem cells into the osteoblastic cell lineage. Besides the interaction between the central and peripheral pathways, the overall effect of leptin on bone might be bimodal depending on leptin serum concentrations. Regulatory pathways triggering osteoblast activity might open new possibilities for anabolic treatment of osteoporosis., V. Cirmanová, M. Bayer, L. Stárka, K. Zajíčková., and Obsahuje bibliografii a bibliografické odkazy